1. Field of the Invention
The present invention relates to a hydraulic control apparatus integrally comprising a hydraulic control unit containing a solenoid valve, and an electronic control unit for controlling the hydraulic control unit. The hydraulic control apparatus, the hydraulic control apparatus of an antilock brake control system in a motor vehicle.
2. Description of the Related Art
When antilock brake control systems were first introduced in automobiles, the hydraulic control unit and electronic control unit were usually installed as separate units connected by a cable.
As shown in Japanese Tokuhyo No. H5-505446 (1993-505446), a hydraulic control apparatus integrally comprising a hydraulic control unit containing multiple are solenoid valves, and an electronic control unit for controlling the hydraulic control unit, was subsequently developed. This apparatus enabled cost and size reductions by eliminating the connector cable and associated connectors, and enabling the hydraulic control apparatus to be installed in a vehicle in a single operation.
This is shown in FIG. 13 of the present patent specification and described below.
An assembly comprising valve block 105 and valve dome 110 corresponds to the hydraulic control unit of the present specification. An assembly comprising electronic components 120 and 120' on a printed circuit board 119, a steel jacket 121 surrounding the outside of a coil 101 to create a magnetic field pattern, and a flexible molding 115 surrounding and securing these parts inside a cover 103, corresponds to the electronic control unit of the present specification.
In a hydraulic control apparatus integrally comprising such a hydraulic control unit and electronic control unit, the coils of the solenoid valves in the hydraulic control unit can be on the hydraulic control unit side or on the electronic control unit side.
When the coils are disposed on the hydraulic control unit side, the coil and electronic control unit must be connected by means of a disconnectable connector structure while the solenoid valve components are all attached to the hydraulic control unit. The structure of the solenoid valve is therefore substantially that of a conventional independent hydraulic control unit.
When the coils are disposed on the electronic control unit side, the coils and electronic circuitry can be directly connected. The problem in this case, however, is that the solenoid valve components become separated between the hydraulic control unit and electronic control unit. More specifically, because the magnetic circuit of the solenoid valves must be closed, a magnetic material must be provided both on the end of the coils connected to the hydraulic control unit and on the opposite end. However this part cannot be preformed as part of the hydraulic control unit, and must be provided with the coils on the electronic control unit side.
In the prior art example shown in FIG. 13, a steel jacket 121 subassembly is disposed as a magnetic member surrounding the coil 101, and must be connected to the printed circuit board 119. Note that there is no waterproof structure provided between the printed circuit board 119 and coil 101 at this stage. A lip seal 122 is therefore formed by covering these parts with a flexible molding 115 in a later process, resulting in a waterproof structure for the printed circuit board 119. Before these subassembly steps can be completed, however, the outside of the coil 101 must be insulated because the steel jacket 121 is connected to the coil 101.
This means that while the task of connecting cables to connect the hydraulic control unit with the electronic control unit is eliminated, the waterproofing means at the connection surface and the task of subassembling the coil 101 before fastening the two units together are not eliminated.